The impact of comorbidities on survival in oral cancer patients: a population-based, case-control study

Figures & data

Table 1. Average CCI score at the time of diagnosis and five years after.

	Average CCI at the time of diagnosis for OSCC patients (95% CI)	Average CCI at the time of diagnosis for the reference group (95% CI)	Average CCI after five years diagnosis of the patients (95% CI)	Average CCI after five years for the reference group (95% CI)
Total	0.76 (0.70;0.82)	0.27 (0.26;0.28)	1.00 (0.96;1.08)	0.38 (0.37;0.39)
Gender
Male	0.79 (0.75;0.83)	0.27 (0.26;0.29)	1.08 (0.99;1.16)	0.39 (0.37;0.41)
Female	0.70 (0.65;0.74)	0.26 (0.25;0.28)	0.91 (0.80;1.02)	0.38 (0.35;0.40)

Table 2 . The odds ratio of specific comorbidities at the time of diagnosis was calculated for patients with OSCC compared to an age-and sex-matched reference group.

Comorbidity	OSCC n (%)	Control n (%)	OR (95%CI)	p-Value
Myocardial infarction	41 (3.5%)	370 (3.1%)	1.11 (0.80:1.54)	.53
Congestive heart failure	4 (0.3%)	9 (0.1%)	4.46 (1.37:14.5)	.01
Peripheral vascular disease	74 (6.3%)	325 (2.7%)	2.40 (1.83:3.10)	<.01
Cerebrovascular disease	66 (5.6%)	480 (4.1%)	1.40 (1.07:1.82)	.01
Dementia	9 (0.8%)	63 (0.5%)	1.43 (0.71:2.88)	.32
Chronic pulmonary disease	78 (6.6%)	464 (3.9%)	18.0 (13.3:24.5)	<.01
Connective tissue disease	33 (2.8%)	219 (1.8%)	1.52 (1.05:2.20)	.03
Ulcer disease	57 (4.8%)	246 (2.1%)	2.38 (1.78:3.20)	<.01
Mild liver disease	61 (5.2%)	78 (0.7%)	8.19 (5.83:11.5)	<.01
Diabetes mellitus	37 (3.1%)	327(2.8%)	1.13 (0.8:1.60)	.47
Hemiplegia	2 (0.2%)	14 (0.1%)	1.43 (0.32:6.3)	.64
Chronic kidney disease	30 (2.5%)	111 (0.9%)	2.75 (1.83:4.13)	<.01
Diabetes mellitus with chronic complications	22 (2.9%)	202 (1.7%)	1.09 (0.70:1.70)	.70
Malignancy, non-metastatic	167 (14%)	22 (0.2%)	88.2 (56.3:138)	<.01
Moderate-severe liver disease	15 (1.3%)	15 (0.1%)	10.1 (4.93:20.7)	<.01
Malignancy, metastatic	9 (0.8%)	1 (.01%)	90.7 (11.5:716)	<.01
AIDS	3 (0.3%)	11(0.1%)	2.73 (0.76:9.81)	.12

OR: Odds ratio; CI: Confidence interval; CCI: Charlson Comorbidity Index; OSCC: Oral squamous cell carcinoma.

Table 3. The odds ratio of specific comorbidities acquired from the date of the OSCC diagnosis up to five years after the diagnosis date was calculated for patients with OSCC compared to an age-and sex-matched reference group.

Comorbidity	OSCC n (%)	Control n (%)	OR (95% CI)	p-Value
Myocardial infarction	17 (1.4%)	203 (1.7%)	0.84 (0.51:1.38)	.49
Congestive heart failure	0 (0.0%)	11 (0.1%)	–	–
Peripheral vascular disease	56 (4.7%)	282 (2.4%)	2.12 (1.58:2.84)	<.01
Cerebrovascular disease	33 (2.8%)	365 (3.1%)	0.92 (0.64:1.32)	.64
Dementia	6 (0.5%)	84 (0.7%)	0.94 (0.41:2.17)	.88
Chronic pulmonary disease	57 (4.8%)	423 (3.6%)	1.41 (1.07:1.87)	.02
Connective tissue disease	8 (0.7%)	167 (1.4%)	0.48 (0.24:0.98)	.04
Ulcer disease	31 (2.6%)	103 (0.9%)	3.16 (2.10:4.74)	<.01
Mild liver disease	35 (3.0%)	60 (0.5%)	6.27 (4.11:9.56)	<.01
Diabetes mellitus	16 (1.4%)	207 (1.7%)	0.77 (0.46:1.29)	.32
Hemiplegia	1 (0.1%)	13 (0.1%)	0.77 (0.10:5.89)	.80
Chronic kidney disease	25 (2.1%)	148 (1.3%)	1.74 (1.13:2.66)	.01
Diabetes mellitus with chronic complications	18 (1.5%)	186 (1.6%)	0.97 (0.60:1.58)	.90
Malignancy, non-metastatic	284 (24%)	918 (7.8%)	3.17 (2.74:3.66)	<.01
Moderate-severe liver disease	17 (1.4%)	33 (0.3%)	5.78 (3.21:10.4)	<.01
Malignancy, metastatic	131 (11%)	124 (1%)	11.9 (9.20:15.3)	<.01
AIDS	1 (0.1%)	8 (0.1%)	1.25 (0.16:10.0)	.83

OR: Odds ratio; CI: Confidence interval; CCI: Charlson Comorbidity Index; OSCC: Oral squamous cell carcinoma.

Figure 1. Kaplan–Meier survival curves stratified CCI score. (A) 5-year overall survival and (B) Recurrence free survival. *This analysis was not age-adjusted. CCI: Charlson Comorbidity Index.

Table 4. Univariate and multivariate analysis of factors affecting overall survival and recurrence free survival -->^a.

		Overall survival					Recurrence free survival
			Univariate		Multivariate			Univariate		Multivariate
	N	Events	HR (95%CI)	p-Value	HR (95%CI)	p-Value	Events	HR (95%CI)	p-Value	HR (95%CI)	p-Value
Age (median)	62	748	1.02 (1.02;1.03)	<.01	1.03 (1.03;1.04)	<.01	808	1.02 (1.01;1.03)	<.01	1.03 (1.02;1.04)	<.01
Gender
Female	433		Reference		Reference			Reference		Reference
Male	740		1.22 (1.05;1.41)	.01	1.27 (1.08;1.49)	<.01		1.13 (0.98;1.30)	.09	1.18 (1.02;1.38)	.03
CCI Score
0	702		Reference		Reference			Reference		Reference
1	192		1.48 (1.25;1.80)	<.01	1.47 (1.20;1.79)	<.01		1.39 (1.13;1.65)	<.01	1.33 (1.10;1.62)	<.01
2	163		1.61 (1.32;1.97)	<.01	1.57 (1.27;1.94)	<.01		1.52 (1.25;1.85)	<.01	1.48 (1.21;1.80)	<.01
≥3	126		1.92 (1.54;2.40)	<.01	1.98 (1.58;2.48)	<.01		1.58 (1.27;1.97)	<.01	1.55 (1.25;1.94)	<.01
UICC-stage
1	310		Reference		Reference			Reference		Reference
2	218		1.79 (1.40;2.28)	<.01	1.47 (1.15;1.90)	<.01		1.61 (1.28;2.02)	<.01	1.42 (1.12;1.79)	<.01
3	156		2.37 (1.83;3.05)	<.01	2.12 (1.61;2.79)	<.01		2.14 (1.69;2.73)	<.01	1.91 (1.47;2.48)	<.01
4	305		3.17 (2.55;3.94)	<.01	2.10 (1.62;2.71)	<.01		2.91 (2.37;3.57)	<.01	2.07 (1.62;2.63)	<.01
Unknown	194		–	–	–	–		–	–	–	–
Anatomical sublocation
FOM^b	462		Reference		Reference			Reference		Reference
Tongue	421		0.87 (0.74;1.04)	.12	0.94 (0.79;1.13)	.52		0.90 (0.76;1.06)	.19	0.97 (0.81;1.14)	.69
Gingiva	132		1.18 (0.93;1.50)	.16	0.90 (0.70;1.17)	.45		1.13 (0.90;1.42)	.28	0.87 (0.68;1.12)	.28
Other	168		1.18 (1.06;1.50)	.01	1.08 (0.86:1.35)	.49		1.13 (1.08;1.43)	<.01	1.12 (0.90:1.38)	.30

^aThis analysis is based on Cox regression, with calculation of 95% confidence intervals (CIs). Variables were coded as categorical except for age, which was a continuous numeric variable. Hazard ratios represent either a comparison with the first reference per group or as a repeated analysis where the hazard ratio represents a comparison with the previous variable in the list.

-->^bFOM: Floor of mouth; HR: Hazard Ratio.